She might have a respiratory infection. If you don't have any antibiotics, you could try VetRX, the feed stores will probably have it, and there are directions. This is an emergency, so I would start with that. I doubt anyone stepped on her. Chicks respond well to antibiotics, so you should consider ordering something to have on hand. I like Oxytet, it is great for respiratory infections. First State Vet supply has it on line, or you can order it other places, too. Duramycin is usually available in feed stores, but it is very weak and not very effective. If you use that, use 4 tsp to a gallon of water. dont follow the dosage instructions, which I think are impossible to figure out anyway.